1. Field
Example embodiments of the inventive concepts relate to a pattern synthesis apparatus which determines pass or fail of a semiconductor device, and to a semiconductor test system having the same.
2. Description of the Related Art
Wafers are formed into complete devices through procedures including a fabrication (FAB) process and a subsequent post-process. The thus-formed devices are categorized into non-defective units and defective units by electrical, thermal and functional tests conducted during or after a packaging process. However, a memory module or device which is commercially available after having been determined to be a non-defective unit may not operate properly when mounted in a personal computer (PC) or a user device including for example a customer end (CE) device.
A semiconductor device to be tested is referred to as a device under test (DUT), and automatic test equipment (ATE), mounting-type test equipment, and fixed frequency mounting-type test equipment are used in testing the DUT.
The ATE tests the DUT using a test pattern based on a semiconductor integrated circuit (IC) defect model obtained through experimentation. The ATE, which may exhibit superior performance in detecting logical failures and parametric failures, however, may be unreliable in terms of accuracy and ease of detection when detecting failures in an actual operation environment. For example, the ATE may have limits in detecting failure patterns in a user device.
The mounting-type test equipment may test the DUT under simulated test conditions of an actual operation environment. In the case of a PC, the mounting-type test equipment may perform a test after fitting the DUT into a socket on a motherboard, thus performing the test in a relatively easy manner. However, when the DUT is welded to a printed circuit board (PCB), a socket may be required to be coupled to the DUT, which may cause distortion in an actual operation environment. Moreover, test patterns applicable to the DUT may be restricted, and the range of the test condition simulation may thus be limited.
The fixed frequency mounting-type test equipment may capture signals input to/output from a semiconductor device in a user device, which operates at a fixed frequency, receives data based on the captured signals, and tests the DUT based on the data. The fixed frequency mounting-type test equipment may provide advantages of both the ATE and the mounting-type test equipment.
However, electronic products with semiconductor devices which are actively variable in operating frequency are increasingly used recently, for example, to satisfy user demand for low power consumption and elongated life of electronic products. It may be desirable to have a semiconductor test system capable of testing pass or fail of semiconductor devices based on frequency variation.